The album's existence was shared by producer and Miller collaborator Thelonious Martin in conversation with DJ Booth. When asked about unreleased music from Miller, Martin confirmed that there is indeed "plenty of it" before expanding on Maclib:

When we was working on "Guidelines," he was always excited about all these other songs. He had this Madlib album, called Maclib. I opened for Madlib in Chicago last summer, at Pitchfork. So I'm opening for Madlib, and about 15, 20 minutes left in my set, Madlib pulls up. Pete Rock walks up as well. So I'm trying to focus and DJ, and Madlib gets on and 15 minutes into his set he just randomly plays a Mac Miller joint. And I turn to him, I'm like, "There's more of these, right?" He's said, "Oh, yeah, there's a whole album. Maclib." What! What! He just kept moving on with his DJ set. If Madlib decides to bless the world with that project, he should.

Elsewhere in the interview, Martin reflects on his friendship and working relationship with Miller. You can read the entire conversation here.